National Comfort Products CPG41838-U, Instruction Manual

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Gas Furnace
On Condensing Models the entire inducer assembly must be disconnected from the flue pipe by
loosening the the 5/16” screw on the worm gear clamp that attaches the rubber connector to
the PVC flue. The (4) ¼” screws will need to be removed to release the housing from the col-
lector box.
If the inducer motor is not running, verify there is a call for heat with a flashing green
light. Then verify that the inducer relay on the control board has closed by checking for the
appropriate voltage between the IND and Neutral terminals on the DSI control board.
Inducer Orifice (Condensing Furnaces Only)
The inducer orifice is installed on the inlet of the inducer assembly and affects the overall sys-
tem pressure.
To access the orifice, you will need to remove the entire inducer assembly.
Furnace Size (Btuh) 25k 32k 43k 50k
Orifice Size (in.)
0.500 0.5265 0.62 0.81
side).
• Look for a restricted flue or venter housing (Mud Wasps nests).
•
Verify the inducer orifice is installed correctly and is the proper size (condensing models)
Inducer Assembly
The inducer assembly included the inducer motor which is powered by 208-230 volts ac from the DSI control board
terminals IND and Neutral.
On non condensing models the inducer motor and wheel are removed from the housing with 3 5/16” screws.
On condensing models the entire inducer assmebly must be disconnected from the flue pipe by loosening the the 5/16”
screw on the worm gear clamp that attaches the rubber connector to the pvc flue. Than 4 ¼” screws will need to be
removed to release the housing from the collector box.
If the inducer motor is not running, verify you have a call for heat with a flashing green light. Then verify that the inducer
relay on the control board has closed by checking for the appropriate voltage between the IND and Neutral terminals on
the DSI control board.
Inducer Orifice (Condensing Furnaces Only)
The inducer orifice is installed on the inlet of the inducer assembly and affects the overall system pressure.
To access the orifice, you will need to remove the entire inducer assembly.
BTU Size 25K 32K 43K 50K
Orifice Size 0.462 0.5265 0.62 0.81
Gas Valve
The gas valve receives a gas supply and regulates gas after a call for heat is initiated. In both models the gas valve is located
in the upper right-hand section of the furnace.
For non condensing models the gas valve is a slow opening valve that is energized from a 24 volt signal sent from the DSI
control board.
side).
• Look for a restricted flue or venter housing (Mud Wasps nests).
• Verify the inducer orifice is installed correctly and is the proper size (condensing models)
Inducer Assembly
The inducer assembly included the inducer motor which is powered by 208-230 volts ac from the DSI control board
terminals IND and Neutral.
On non condensing models the inducer motor and wheel are removed from the housing with 3 5/16” screws.
On condensing models the entire inducer assmebly must be disconnected from the flue pipe by loosening the the 5/16”
screw on the worm gear clamp that attaches the rubber connector to the pvc flue. Than 4 ¼” screws will need to be
removed to release the housing from the collector box.
If the inducer motor is not running, verify you have a call for heat with a flashing green light. Then verify that the inducer
relay on the control board has closed by checking for the appropriate voltage between the IND and Neutral terminals on
the DSI control board.
Inducer Orifice (Condensing Furnaces Only)
The inducer orifice is installed on the inlet of the inducer assembly and affects the overall system pressure.
To access the orifice, you will need to remove the entire inducer assembly.
BTU Size 25K 32K 43K 50K
Orifice Size 0.462 0.5265 0.62 0.81
Gas Valve
The gas valve receives a gas supply and regulates gas after a call for heat is initiated. In both models the gas valve is located
in the upper right-hand section of the furnace.
For non condensing models the gas valve is a slow opening valve that is energized from a 24 volt signal sent from the DSI
control board.